Servers receive various kinds of queries and typically forward them to other servers for processing results responsive to the query. For example, individuals accessing the Internet with computing devices may submit queries to search engines or other services that search databases and provide relevant results to the queries. A single search service can require numerous networked servers to handle all the queries received from computing devices. A query transmitted to such a search service may be received by a front-end server that does not immediately return results to the query but instead forwards the query to another server, sometimes called a back-end server, for identification of results that are responsive to the query. Numerous back-end servers can exist and the front-end server can distribute queries among the backend servers to ensure that work is evenly distributed.
Back-end servers, upon receiving queries from front-end servers, can access one or more datastores that include information potentially relevant to the query. The back-end server, or other computing devices in communication with the back-end server, sort through the information to determine specific entries that are responsive to the query. The responsive entries (i.e., the search results) are returned to the querying computing device for presentation to an individual that submit the query. A back-end server may be capable of storing a copy of the search results relevant to the query (sometimes called a cache). Upon receiving an identical query, the back-end server could return a cached result instead of accessing the datastore in order to save time and computer resources.